The principal aim is to isolate, characterize and clinically utilize human leukemia-lymphoma-associated (HLL) antigens of human malignant cells. We are isolating large quantities of purified HLL antigens using cultured leukemia-lymphoma cells, so that we can carry out detailed studies on the immunological and chemical properties of HLL antigens. The antigens isolated will be useful in obtaining strong, specific antisera to HLL antigens. Such antisera will in turn be useful for diagnostic purposes. The HLL antigens which we have been detecting are found on the surfaces of cells. We have also found much of HTL antigen activity on isolated cell membrane preparations. Therefore, we are isolating these antigens from cell membranes prepared from cultured leukemia-lymphoma cells. The cell membranes are treated with deoxycholate to solubilize the HL antigens. The solubilized antigens are fractionated by gel filtration and affinity chromatography.